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Wrong size Starfinder

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#1 cheapersleeper

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Posted 27 January 2013 - 08:54 PM

I have been using an OTA from an EQ mounted 10" f4.5 Starfinder on a Dob mount for several years. Just got a Starfinder EQ mount from one of our esteemed CN members and after a clean up it looked so great that I went and got that big OTA and tried to put it on. Ooops. Straps are too short and the radius of the plate the tube rests on is too small. Anyone have a non-destructive idea for getting that bigger tube on that smaller plate? I assume I can find something to use as strap material...

Thanks in advance,
Brad

#2 bendab

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Posted 28 January 2013 - 06:40 PM

I have a 8" starfinder EQ I know the 10" used the same mount maybe you have a mount for a 6" starfinder in that case is the mount even big enough for the 10" starfinder something to think about could be to small with the extra weight.....

#3 cheapersleeper

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Posted 28 January 2013 - 10:01 PM

Indeed. When I hefted the OTA on to it the saddle the smaller radius cut into the saddle looked far enough off from the OD of the bigger tube to require a different saddle. Reading more and poking around and putting that tube on it again it does seem that it will work and that the same one was used with all models. I do need to lengthen the straps and I think I will make some spacers to get a more robust mechanical connection between scope and mount. We shall see.

B

#4 rmollise

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Posted 29 January 2013 - 07:08 AM

I have a 8" starfinder EQ I know the 10" used the same mount maybe you have a mount for a 6" starfinder in that case is the mount even big enough for the 10" starfinder something to think about could be to small with the extra weight.....


Negative. The 6-inch mount was exactly the same as the one used on the 8 and 10. Only the 16 was different. The only difference is the straps.

#5 grendel

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Posted 29 January 2013 - 07:38 AM

nylon ratchet luggage straps? would they do the job like these -
http://www.wilkinson...m-ratchet-5m...
Grendel

#6 cheapersleeper

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Posted 29 January 2013 - 08:56 AM

Thanks, Unc, for that confirmation. I had already kinda sorta figgered that out.

Grendal, maybe so. I am kicking around some thoughts on how to get this thing as robust as I can.

Gracias,
El Brad

Also: If I decide to disassemble the beast for a clean and lube, what kind of lube should I use? I am guessing there are no beautifully machined ball bearings in there...
B

#7 Pitter

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Posted 02 February 2013 - 12:46 AM

You are correct. No ball bearings. Only the 16" had ball bearings. Yours will be plastic. There is really nothing to grease.

#8 rmollise

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Posted 02 February 2013 - 09:09 AM

Yep, nothing at all that should need grease. This mount will handle your 10-inch well--the 8-inch with its longer tube was more of a challenge for it. As long as the drive is working, you should be good to go. Several folks used to sell tube rings for this mount--the straps are nowhere and you wouldn't like 'em even if they were the right size. ;)

#9 cheapersleeper

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Posted 03 February 2013 - 09:37 AM

Well, Sir, a trip to Ace got me some straps and someone has pointed me toward a lazy susan that some have used for rings for later so I may drag the beast out soon.


Regards,
Brad

#10 Geo.

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Posted 03 February 2013 - 11:39 AM

As long as the drive is working, you should be good to go.



In my experience the 120AC drives have fewer issues than the microprocessor controlled DC drives. The Starfinder DC drives are similar in design to the Meade LX50 and seem to have the same sensitivity errant EMF. The weakness seems to be the PIC16C57 microprocessor. C is for CMOS memory, which doesn't like static or power surges.

#11 cheapersleeper

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Posted 06 February 2013 - 06:06 PM

Thanks, George. I am DC and doubt that I could find an AC if I wanted to so I will endeavor to live with it.

Regards,
Brad

#12 cheapersleeper

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Posted 06 February 2013 - 06:10 PM

Is it worth tearing this beastie down for a clean and lube and if so, where would I find a "ow to?" Most importantly how to adjust the worm and gear and that amazing slip clutch. Does it need lube and if so, what kind?

Regards,
Brad

#13 rmollise

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Posted 06 February 2013 - 06:19 PM

AC is as close as a battery and a small inverter...

#14 cheapersleeper

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Posted 06 February 2013 - 06:35 PM

I am not really sweating it at this time, sir. What I am mainly sweating is that this thing takes up more room than my 12" Dob and I built the Dob BIG. I do have the feeling, though, that if I get it working and presentable looking that the venerable Starfinder will be a hit at public viewing events.

Also, Unk, please grant me forgiveness for continuing to want to tear down and lube that mount even after you told me I don't need to... :smash:

Best Regards,
Brad

#15 Pitter

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Posted 06 February 2013 - 06:35 PM

I'm a bit confused. The starfinder came with AC drive. Has yours been converted to DC? If the gear needs adjusting just loosen or tighten the adjusting screw inside the motor housing. Really no lube needs to be applied to the motor but use it sparingly if you do. You don't want to gum it up.

#16 cheapersleeper

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Posted 06 February 2013 - 06:42 PM

Some were DC...

...like mine. Nice factory installation with a spiffy battery door on the back of the motor housing.

B

#17 Pitter

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Posted 06 February 2013 - 09:13 PM

Thanks for that info Brad. I guess they must have switched to DC in the late 90's.

#18 apfever

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Posted 07 February 2013 - 05:47 AM

Brad,

Can you post some pictures of your mount? I've had about 5 of these go through here recently. I currently have the Meade 826 mount and the Starfinder mount. My 10" is the starfinder, my 8" is the Meade 826. My Starfinder is the 12V.

#19 cheapersleeper

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Posted 07 February 2013 - 06:05 AM

Hey, apfever, thanks for dropping in, I was hoping you would. I will try to post a pic or two. Right now the Telecom Network Monster has me working over time! ROWR!! Hope to get pics up maybe this afternoon.

I saw your teardown thread, I think it was the 826? Looking forward to your input.

Regards,
Brad

#20 apfever

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Posted 08 February 2013 - 05:44 AM

Brad,

Yeah I did a complete run through on an 826. I don't think I posted all the motor assembly and clutch rebuild. Everything is dialed in with calipers or mic. The 826 is a straight 120V.
The Starfinder is a different animal.
The 826 has a fairly flat saddle that rings bolt to. The starfinder saddle is a a single molded unit with curved ends. However, mine has dual curved radii. The very tips of the curve are slightly flatter to fit a larger radius.

#21 cheapersleeper

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Posted 08 February 2013 - 06:08 AM

Yeah, that saddle on the Starfinder is quite odd. Given the size and weight of the 10" OTA I would rather it be as close to the mount as possible but this seems to work. I guess if the cold and clouds allow, it would be reasonable to try the thing out before I get to messing with it.

B

#22 rmollise

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Posted 08 February 2013 - 09:09 AM

I'm a bit confused. The starfinder came with AC drive. Has yours been converted to DC? If the gear needs adjusting just loosen or tighten the adjusting screw inside the motor housing. Really no lube needs to be applied to the motor but use it sparingly if you do. You don't want to gum it up.


Early StarFinders had AC drives and metal focusers. Later models had DC drives (which could use the Magellan II) and platic focusers. Otherwise, the same. ;)

#23 Pitter

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Posted 08 February 2013 - 02:07 PM

Thanks Rod

#24 cheapersleeper

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Posted 08 February 2013 - 08:05 PM

Pics:

Posted Image

Posted Image


B

#25 cheapersleeper

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Posted 11 February 2013 - 12:24 AM

Cranked it up tonight and the motor turns. I let it sit with the motor on for a while after zeroing out the RA circle and with that super light load it was tracking. Outside with the big 10" OTA and the counterweights needed to balance it, it was not tracking. I would think this points to my needing to adjust the clutch since the guy I got it from was using much lighter OTAs on it.

What think you, smart people?

Regards,
Brad






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